Elastic-fluid compressor.



,M. LEBLANG.

ELASTIC FLUID COMPRESSOR.

APPLICATION FILED D20. 6, 1011.

Patented Aug. 13, 1912.

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'n c tmw 1 Qua/ a UNITED sTAtrEs PATENT OFFICE.

MAURICE LEBLANC, OF (i110 SSY, FRANCE, ASSIGNOR TO STE AME POURLEXPLOITA- TION DES PROCED S WESTINGHOUSE LEBLANC, OF PARIS, FRANCE.

ELASTIC-FLUID COMPRESSOR.

Specification of Letters Patent.

Application filed December 5, 1911. Serial No. 664,086.

To all whom it may concern:

Be it known that I, MAURICE LnBLANo, a citizen of the Republic ofFrance, residing in Croissy, Seine-et-Oise, France, have inof severalhundred meters per second what- .compressing units operating bycentrifugal ever may be their angular speed, which is necessary if thecompressor is to be used not only for compressing air taken in at theatmospheric pressure but also for producing and maintaining a highvacuum in an inclosed space.

The compressor which forms the object of this invention is composed ofseveral force and associated in series. The g'eneral arrangement issimilar to that of all apparatus of the kind.

The novel feature of the invention resides in the construction of therotors and in particular the constitution of their blades.

Figure 1 of the accompanying drawings is a longitudinalsection throughthe compressor. Fig. 2 is a transverse section and Fig. 3 a longitudinalsection through one of the rotors. Fig. 4: is a diagrammaticrepresentation of one of the blades drawn to an enlarged scale and seenin end view, showing that its profile is such that the blade has umfornreslstance. Fig. 5 is an end elevation of one of the blades and Fig. 6is a fragmentary side elevation thereof. The blade shown is rectangular,in side elevation. It may have any suitable profile provided that thewidth of the blade diminishes with the distance from the base and thatits thickness decreases.

' The blade suddenly expands at its base so ery of the nave for thepurpose of receiving the heels 2 of the blades. To maintain the bladesin place laterally, circular cells (Fig. 3) are provided at the ends ofthe nave on each si e of the notch receiving the heel. Into these cellsare introduced segments 4, 4, which expand, owing to their elasticity,and are held in place during working against the bottom of the cells bycentrifugal force. p

The blades constructed according to this invention are made of vegetablefibers, such as hemp, cotton, flax, or preferably ramie, united togetherby a suitable ag lutinant, such as caoutchouc, balata, lori viscose,gelatin, a resin or a suitable gum. For the sake of illustration it maybe supposed that caoutchouc is used.

The blades are made in the following manner :-A cylinder is covered witha helix of very close turns, consisting of a very homogeneouslymanufactured thread of the selected vegetable fibers, the winding beingunder tension. The whole is then painted over with a solution ofcaoutchouc containng sulfur and the cylinder is introduced into a stovefor drying the solution and causing the threads to adhere to'each other.This covering is then out along a generatrix of the cylinder andunrolled. In this manner there is obtained a very thin rectangular bandcomposed of rectilinear threads stretched parallel to each other andcontiguous with each other (Fig 6). A number of these bands of differentlength are now folded over an ebonite wedge, such as that shown at 5 inFig. 5, the arrangement being such that the super-position of the bandsforms a body having substantially a profile of uniform resistance. Theassemblage of bands is now introduced into a two part mold, the internalsurface of which is stepped so as to follow the form of the blade, andis forcibly pressed therein. The mold is then introduced into thevulcanizing stove. When vulcanization is complete .it only remains toremove the blade from the mold. There are thus obtained ebonite bladesstrengthened by vegetable fibers in the direction of their length butnot in the direction of their width. Every precaution should be takenthat in the course of the Patented Aug. 13, 1912.

manufacture, the mass of agglutinant used Iio The mode of manufacturedescribed above is given only by wayof example; it may be varied notablywith the nature of the agglutinantiselected and with the treatmentwhich" determines the selection.

The blades thus made present the following advantages:

1. Their density is close to that of water. The tenacity of thevegetable fibers is sufli-- ciently great to enable them to resistcentrifugal force better than the. fibers of steel which are seven toeight times as dense. This is a known fact, witness the manufactureofaeroplane propellers ofwood instead of metal, owing to the highperipheral angular speeds that they are to attain. This result would notbe obtained if the blades were made of bands of cloth in which thethreads of the warp were stretched in the direction of their length. Thethreads of the weft would increase the mass of the blade without addinganything to its resistance in the longitudinal direction. They would 1give it, it is true, high resistance in the. transverse direction, butthat is useless, since the blade has no strain to support in thisdirection.

2. These blades do not sufi'er appreciably more elongation under theinfluence of centrifugal force than metallic blades of the same profiledo. Moreover, they do not become deformed. This is because the threadshave been stretched beforehand and could only become longer if theconstituent fibers were themselves to be extended; On the other hand ina cloth fabric the threads are engaged with each other and have a wavyform. When a band of cloth is stretched in the direction of the warp forexample the threads of the 'latter first straighten themselves and aremuch extended before the constituent fibers are appreciably extended.During this time the waviness of the weft threads is increased and theblade is deformed.

3. The blades have to turn between two metallic plates a ainst whichthey may rub.

without injuring" hem. The bladeswear at their edges, being ground topowder, which is immediately thrown outwardlywuntil the friction ceases.If the blades were of metal each rotor would actas a cutter on theplates and would soon put them out of use. Thus the blades may be alittle too wide in the first instance and may be turned between theplates at a reduced speed for the purpose of wearing them. The mostsimple arrangement is to have only extremely small play, this beingallowable only in compressors of low power.

4. The blades keep themselves straight, all their fibers remainingperpendicular to the true axis of rotation under the influence ofcentrifugal force, the elasticity of the aig glutinant permitting themto move slightly relatively to each other. The action of the bladescannot develop any appreciable couple on the nave or on :the shaft whichcarries it, as would happen if they were metallic. The flexibility ofthe blades dispenses with the use ofa flexible shaft.

Having thus described my invention and the best means I know of carryingthe same.

into practical effect, I claim 1. In a rotary elastic fluid compressor,blades composed of vegetable fibers stretched parallel to each otherradially to the rotor and united together by a suitable agglutinant,substantially as described.

2. In a rotary elastic fluid compressor, blades composed of fibrousmaterial extended longitudinally of the blade and united by anagglutinant. I,

In witness whereof, I have hereunto signed my name in the presence oftwo subscribing witnesses.

MAURICE LEBLANC.

Witnesses:

Jonas ARMENGAUD, Jeune, 1F ERNAND BARRF'J.

